Average evoked responses (AER) to varying intensities of electrical stimulation to the forearm and subjective ratings of these stimuli have been studied in a total of 62 patients with affective disorders and 33 age-and sex-matched normal volunteers. In 12 patients, urinary 3-methoxy 4-hydroxy phenyl glycol (MHPG) was collected during the stimulation session and during a second control session. Other studies demonstrated specific AER correlates of audioanalgesia in normal volunteers.